There exists a wide variety of situations wherein it is desirable to fixate adjacent bone pieces or segments to promote healing of a fracture. Such situations occur, for example, whenever a fragment of the greater trochanteric portion of the femur bone needs to be fixated to the shaft of the femur.
With the aging demographics of many industrialized countries, hip related surgical procedures are becoming increasingly prevalent. An example of such procedures is the so-called total hip replacement surgery or arthroplasty which is typically performed as a consequence of osteoarthritis of the hip joint. The procedure involves replacing the diseased cartilage and bone of the hip joint with artificial materials including an artificial prosthesis.
During the procedure, a segment of the greater trochanteric portion of the femoral bone is typically temporarily osteotomized, that is a the greater trochanter is surgically separated from the proximal end of the femur so that the soft tissue attached to the greater trochanter can be moved aside in preparation for implantation of the femoral stem of the replacement prosthesis into the medullar canal of the femoral shaft. Once the femoral stem of the prosthesis is seated within the medullar canal in the femur, the greater trochanter is re-attached to the proximal end of the femur.
The greater trochanter is subjected to considerable stress imparted thereon by anatomical structures such as muscles attachments during normal use of the hip. Accordingly, mechanical fixation of the greater trochanter to the femoral shaft is mandatory in order to promote healing of the fracture created by the osteotomizing step of the hip replacement procedure or traumatic injury.
Also, because of the considerable stress imparted on the greater trochanter as a consequence of the total hip arthroplasty procedure, it is estimated that this type of procedure is associated with a relatively high percentage of greater trochanter post-surgical fractures, which, in turn, may require fixation.
Other examples of situations wherein fixation of the greater trochanter to the femur shaft is required include trochanter and/or proximal femur reconstruction, corrective or revision hip surgery and the like.
One relatively common prior art method for fixating the greater trochanter to the proximal femur shaft is a so-called “cerclage” fixation technique wherein a flexible member, such as a cable, is drawn tight and clamped in order to encircle the target fixation site and to hold the bone portions together until they have time to heal.
Typically, the surgical cables are implanted using tensioning devices which apply tension to a surgical cable looped around the bone. Crimps are then added and deformed to clamp the cable loop in place.
The so-called “cerclage” methods, although somewhat useful, are associated with a number of drawbacks. For example, such procedures are typically considered relatively complex. Furthermore, cable failure, migration or loosening may lead to fixation loss and non-union of the bone fragments with clinical consequences such as pain, lack of functionality and the like.
Other types of components have been devised in attempts to provide solutions for fixating the greater trochanter to the femur shaft. For example, some components include a bone grip for engaging over the trochanter and a plate portion for extending down over the shaft of the femur.
A well known typical example of such type of component is the so-called “Cable-Ready” (a registered trade mark) greater trochanteric re-attachment system developed by Zimmer. This system involves the use of a component which has a substantially straight, flat and elongated plate portion, integral with a hooked portion terminating in a spike. Ideally, the hooked grip portion lies over the greater trochanter, and the plate portion overlies the shaft of the femur. Both portions have apertures to receive “cerclage” cables, which are passed around the bone, to secure the device in place.
Again, although somewhat useful, such devices also suffer from numerous drawbacks. Indeed, as is well known, the greater trochanter lies laterally, close to the skin, and can be easily palpated on the lateral side of the thigh. Because it is the most lateral point of the hip region, the greater trochanter may cause discomforts when lateral pressure is exerted on the side of the body such as when an individual lies on his or her side on a hard surface. Most prior art fixation plates increase the discomfort by being located over the most prominent portion of the greater trochanter. Also, some prior art devices require that relatively large incisions be performed in large leg muscles to position them properly over the greater trochanter, with all the discomfort and risk for complications associated with such operations.
Accordingly, there exists a need for an improved orthopaedic fixation component and it is a general object of the present invention to provide such an improved orthopaedic fixation component.